Flexible bench-scale recirculating flow CPC photoreactor for Solar photocatalytic degradation of methylene blue using removable tioimmobilized on pet sheets

Abstract

TiOimmobilized on polyethylene (PET) nonwoven sheet was used in the solar photocatalytic degradation of methylene blue (MB). TiOEvonik Aeroxide P25 was used in this study. The amount of loaded TiOon PET was approximately 24%. Immobilization of TiOon PET was conducted by dip coating process followed by exposing to mild heat and pressure. TiOPET sheets were wrapped on removable Teflon rods inside home-made bench-scale recirculating flow Compound Parabolic Concentrator (CPC) photoreactor prototype (platform 0.7 × 0.2 × 0.4 m3). CPC photoreactor is made up of seven low iron borosilicate glass tubes connected in series. CPC reflectors are made of stainless steel 304. The prototype was mounted on a platform tilted at 30°N local latitude in Cairo. A centrifugal pump was used to circulate water containing methylene blue (MB) dye inside the glass tubes. Efficient photocatalytic degradation of MB using TiOPET was achieved upon the exposure to direct sunlight. Chemical oxygen demand (COD) analyses reveal the complete mineralization of MB. Durability of TiOPET composite was also tested under sunlight irradiation. Results indicate only 6% reduction in the amount of TiOafter seven cycles. No significant change was observed for the physicochemical characteristics of TiOPET after the successive irradiation processes.